The devastating heatwave that has baked India and Pakistan in recent months was made more likely by climate change and is a glimpse of the region’s future, says a study by international scientists.
The World Weather Attribution group analysed historical weather data that suggested early, long heatwaves that affect a massive geographical area are rare, once-a-century events.
But the current level of global warming, created by human-caused climate change, has made those heatwaves 30 times more likely, said the group’s study released on Monday.
If global heating increases to 2 degrees Celsius (3.6 degrees Fahrenheit) more than pre-industrial levels, then heatwaves like this could occur twice in a century and up to once every five years, said Arpita Mondal, a climate scientist at the Indian Institute of Technology in Mumbai, who was part of the study.
“This is a sign of things to come,” Mondal said.
For example, “in a 2C warmer world, what is a one in 100-year event now can be as frequent as a one in five-year event,” Mondal told a news briefing.
To conduct their analysis, the scientists compared temperature data readings for the months of March and April dating back several decades with what conditions might have been without climate change, based on computer simulations.
“People in South Asia are used to some level of hot temperatures,” said Roop Singh, climate risk adviser at the Red Cross Red Crescent Climate Centre. “But when it gets to 45C or over, it becomes really difficult to carry out regular activities.”
In fact, the results of the World Weather Attribution group are conservative. An analysis published last week by the United Kingdom’s Meteorological Office said the heatwave was probably made 100 times more likely by climate change, with such scorching temperatures likely to reoccur every three years.
The World Weather Attribution analysis is different as it is trying to calculate how specific aspects of the heatwave, such as the length and the region affected, were made more likely by global warming.
“The real result is probably somewhere between ours and the (UK) Met Office result for how much climate change increased this event,” said Friederike Otto, a climate scientist at the Imperial College London, who was also a part of the study.
What is certain, though, is the devastation the heatwave has wreaked. India sweltered through the hottest March in the country since records began in 1901 and April was the warmest on record in Pakistan and parts of India.
The effects have been cascading and widespread: a glacier burst in Pakistan, sending floods downstream; the early heat scorched wheat crops in India, forcing it to ban exports to nations reeling from food shortages due to Russia’s war in Ukraine; it also resulted in an early spike in electricity demand in India that depleted coal reserves, resulting in acute power shortages affecting millions.
Then there is the effect on human health. At least 90 people have died in the two nations, but the region’s insufficient death registration means that this is likely an undercount.
South Asia is the most affected by heat stress, according to an analysis by The Associated Press of a dataset published by Columbia University’s climate school.
India alone is home to more than a third of the world’s population that lives in areas where extreme heat is rising.
Experts agree the heatwave underscores the need for the world to not just combat climate change by cutting down greenhouse gas emissions, but to also adapt to its harmful effects as quickly as possible.
Poor, children and elderly at risk
Children and the elderly are most at risk from heat stress, but its effect is also inordinately bigger for the poor who may not have access to cooling or water and often live in crowded slums that are hotter than leafier, wealthier neighbourhoods.
Climate risk adviser Singh said daily wage labourers, such as street vendors and construction workers, are also hard hit as they may not have a cool place to rest and recover. She said experts expect the heatwave’s death toll to rise as more data is reported to officials.
Rahman Ali, 42, a ragpicker in an eastern suburb of the Indian capital New Delhi, earns less than $3 a day by collecting waste from people’s homes and sorting it to salvage whatever can be sold. It is backbreaking work and his tin-roofed home in the crowded slum offers little respite from the heat.
“What can we do? If I don’t work … we won’t eat,” said the father of two.
Some Indian cities have tried to find solutions.
The western city of Ahmedabad was the first in South Asia to design a heatwave plan for its population of more than 8.4 million, all the way back in 2013. The plan includes an early warning system that tells health workers and residents to prepare for heatwaves, empowers administrations to keep parks open so that people can shade and provides information to schools so they are able to tweak their schedules.
The city has also been trying to “cool” roofs by experimenting with various materials that absorb heat differently. Their aim is to build roofs that will reflect the sun and bring down indoor temperatures by using white, reflective paint or cheaper materials like dried grass, said Dr Dileep Mavalankar, who heads the Indian Institute of Public Health in the western Indian city Gandhinagar and helped design the 2013 plan.
Most Indian cities are less prepared and India’s federal government is now working with 130 cities in 23 heatwave-prone states for them to develop similar plans.
Earlier this month, the federal government also asked states to sensitise health workers on managing heat-related illnesses and ensure that ice packs, oral rehydration salts and cooling appliances in hospitals were available.
But Mavalankar, who was not part of the study, pointed to the lack of government warnings in newspapers or TV for most Indian cities and said that local administrations had just not “woken up to the heat”.